1. Field of the Invention
The present invention relates to medical devices. More particularly, the invention relates to the field of endoscopic and laparoscopic medical devices used primarily in minimally-invasive surgery.
2. Background of the Invention
Access sheaths, such as ureteral access sheaths, may be used to gain access to body cavities in lumens during endoscopic and laparoscopic surgery, and by other procedures that generally use minimally invasive techniques. Thus, ureteral access sheaths may be used with an endoscope for finding and removing kidney stones, and may be used in other applications, such as access to bile ducts. Other applications for which an access sheath has been used include vascular procedures, as well as procedures requiring gastro-intestinal access, uterine access, and bronchial access. Thus, sheaths may be used in combination with endoscopes, hysteroscopes, sigmoidoscopes, bronchoscopes, and many other types of instruments for minimally-invasive techniques.
Using a sheath provides for a way to protect the tissues of a patient during a procedure. For instance, if a kidney stone is to be removed, a retrieval basket may require many passages back and forth across the patient's ureter to remove stone fragments. Passing the basket through the access sheath instead of the ureter itself avoids trauma to the ureter and the surrounding tissues.
One problem that is common to many procedures in which these devices are used is that more and more is expected from the surgeon and the operating team. For instances, now that an access sheath may be used to access across a ureter, the surgeon may wish to use the sheath for access not only for an endoscope, but also for multiple endoscopic instruments, such as a retrieval basket, a stone “blocker” or back stop, a fiberoptic laser to break up stones, a safety wire, an operating wire, or a system to provide irrigation or to instill contrast agents. While all of these systems are desirable, it is difficult to operate them all at the same time and through the same access sheath. Thus, the surgeon may also pass instruments through the endoscope as well as the access sheath.
Removal of kidney stones and other calculi within body cavities may be accomplished with an endoscope or other expensive piece of equipment. An endoscope is inserted into the patient, desirably using a body passageway, such as a ureter or a blood vessel. An endoscope includes an integral optical system, a working channel, and a way to maneuver the endoscope so that the surgeon can accomplish a therapeutic or diagnostic procedure. The surgeon positions the endoscope so that the surgeon can observe the desired body part of the patient using the optical system, with irrigation if necessary. The surgeon then uses at least one instrument, such as a laser or a grasper, to break up and remove objects in the body passageway. The endoscope may also be used for diagnostic purposes, such as for observing the desired portion of the patient and then taking a biopsy sample.
Flexible endoscopes are very expensive pieces of equipment. When this application refers to endoscopes, primarily flexible endoscopes are intended. They may cost from $10,000 to $20,000 and are typically used for no more than 10-15 procedures before they require a $3,000 to $5,000 overhaul. Part of the problem may be the very extensive cleaning and sterilization that is required after each use on a patient. After the overhaul, the endoscope may typically be serviceable for only another 10 procedures before requiring an additional overhaul. Thus, endoscopes are very expensive and they require a great deal of attention and maintenance. Because damage is not always apparent to hospital personnel, the need for repair or overhaul on the endoscope may become obvious during a medical procedure, causing a delay in completing the procedure. Thus, it may be necessary to keep multiple endoscopes in stock to ensure their availability at all times.
What is needed is a more effective way to access body cavities during endoscopic and laparoscopic surgery including an ability to navigate through tortuous body passageways and cavities while allowing for important access functions.